Railway signaling system



July 27, 1937. P. H. cRAGo 2,088,030

RAILWAY SIGNALING SYSTEM Original Filed Oct; 6, 1932 2 Sheets-Sheet 1 v 9 l'maneni Magnet l 1 W W 4 4 U; 25

L. INVENTOR Ll Ll PaulHCPago HIS A TTORNEY July 27, 1937. P. H. CRAGO RAILWAY SIGNALING SYSTEM Original Filed Oct. 6, 1932 2 Sheets-Sheet 2 R o H m w M w mfi mg m M @m mwk .4 0m Q i i w PM mm fi Q Qvw @Q w av 6 6 raw bfi w iv m R N n mm kwv 3 0% 0 E m m U m AN mm 6 m Patented July 27, 1937 UNITED STATES PATENT OFFICE RAILWAY SIGNALING SYSTEM Paul H. Crago, Wilkinsburg, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania My invention relates to railway signaling systems, and particularly to systems of the type involving a polarized electromagnetic device having a neutral armature and. a polar armature.

I will describe two forms of systems embodying my invention, and will then point out the novel features thereof in claims.

The present application is a division of my copending application Serial No. 636,475, filed October 6, 1932, for Electromagnetic apparatus and which is now U. S. Patent No. 1,962,234, dated June 12, 1934.

In the accompanying drawings, Fig. 1 is a View showing in front elevation one form of electromagnetic device which may be used in systems embodying my invention. Fig. 2 is a diagrammatic view showing one form of system embodying my invention. Fig. 3 is a diagrammatic View showing another form of system also embodying my invention.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, the device in the form here shown, comp-rises an electromagnet M having an operating winding 3 and a secondary winding 4 in inductive relation to the operating winding. In actual practice this magnet comprises two= cores each provided with an operating winding which windings are connected in series, and each also provided with a secondary winding which windings are likewise connected in series, but one of the cores with its associated windings is directly behind the other in the drawings. A neutral armature l pivotally mounted at the point 8, is controlled by the pole pieces 18 of the magnet M. The electromagnetic apparatus also involves the usual permanent magnet 5 which, together with the neutral magnet M, controls a polar armature 20. The operating wind-, ing 3 is supplied with current from a battery 29 through a pole-changer 30.

As shown in the drawings, the electromagnet M is applied to a Searchlight type of light signal, which signal is disclosed and claimed in an application for Letters Patent of .the United States, filed by A. E. Dodd on October 6, 1932, Serial No. 636,526, for Light signals. Briefly described, the signal portion .of the device comprises a member 9 attached to the neutral armature 'l and provided witha stop screen R, as well as a recess 3 l these parts being so arranged that the screen R orgthe recess 3! will be in front of a lamp L according as armature 'l' is in the released or the attracted position. A second member I0 is pivotally attached to the member 9 at point H and is movable between two stops l2 and I3 which are fixed to the member 9. The member III is provided with a proceed screen G and a caution screen Y, one or the other of which will register with the lamp L according as the member In is in its lower or its upper position, and provided, of course, that the recess ill of member 9 is in front of the lamp. Member I0 is operated by the polar armature 26 through the medium of a hook 2| and a link 22 provided at its upper end with a hook 22 Link 22 is restrained to move in a vertical direction by a guide 23 attached to the member 9.

The reference character K designates an auxiliary magnet having a winding 25. In actual practice this magnet will usually comprise two cores each provided with a winding, which windings are connected in series. Magnet K has pole pieces 26 which coact with an auxiliary armature 21 attached to neutral armature l by a bar 28. The parts are so arranged that when the armature l is closed and magnet K is energized, the armature. 1 will be held in its attracted position. The apparatus also involves a second auxiliary magnet K comprising two parallel cores (only one of which is shown in the drawings) each core being provided with a winding 4| which windings are connected in series. This magnet has pole pieces 42 coacting with the armature 21 in such manner that when the: neutral armature l is in the released position and magnet K? is energized, it will hold the armature 'l in such position. The circuits for magnets K and K are controlled by a front contact 4lJ--- lll and a back contact 40-40 operated by the neutral armature I. When the neutral armature I is in its attracted position, the front contact 40-40 is closed and winding 25 of magnet K is then connected with the secondary winding 4 of the magnet M. When the neutral armature 1 is in its released position back contact 40-46 is closed, and the winding 4| of auxiliary magnet K is then connected with the secondary winding 4.

The operation of the device illustrated in Fig. 1 is as follows: When pole-changer 30 is in the position shown in the drawings, which I will assume to be its normal position, operating wind,- ing 3 is supplied with current of normal polarity, so that neutral armature 1 is in its attracted position and the polar armature is in its normal position. If now the pole-changer 30 is reversed, thereby reversing the polarity of the current supplied to the winding 3, the-polar armature 20 will be reversed,.but the neutral armature l will be held in its attracted position by magnet K owing to the surge of current supplied to the winding of this magnet by the auxiliary winding 4. I will now assume that the neutral armature I is released, thereby connecting magnet K with winding 4, and that the operating winding 3 becomes energized. The surge of current which will then be supplied to magnet K will serve to hold armature l in the released position for an appreciable interval of time, so that this armature is slow to pick up when magnet M becomes energized.

Referring now to Fig. 2, the reference characters and 36 designate the track rails of a stretch of railway track along which traffic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 39 to form track sections, of which only one complete section is shown in the drawings. Each section is provided with the usual track circuit comprising a battery 31 and a track relay 38. Each section is also provided with a light signal of the type shown in Fig. l, the only elements of this signal which are shown in Fig. 2 being the operating winding 3, the secondary winding 4 and the first auxiliary magnet 25. The operating winding 3 is provided with a circuit which includes contact 33 of track relay 38, and the pole-changer 30, which, as here shown, is operated by the neutral armature of the signal for the next section in advance. Furthermore, the circuit for the auxiliary magnet winding 25 includes a front contact 34 of the associated track relay 38 so that this circuit is open when the associated track section is occupied.

When a train enters the track section shown in Fig. 2, it will deenergize relay 38, thereby deenergizing the operating winding 3 of the associated signal and also opening at contact 34 the circuit for the auxiliary magnet winding 25. This destroys what would otherwise be a slotv releasing characteristic of the apparatus and so insures that the sign-a1 will assume the stop indication without delay. When the train passes into the section next in advance, it may allow the track relay 38 for the section which the train is leaving to pick up before the track relay for the section which the train is entering becomes released. In this event, winding 3 for the signal in the rear will be momentarily energized, but due to the slow pick-up characteristic of the armature 1, this signal cannot be operated to momentarily flash the proceed indication during the change from the stop to the caution indication.

Referring to Fig. 3, the reference characters 43 and 44 designate the track rails of a stretch of railway track along which traific may normally move in either direction. These rails are divided by means of insulated joints 39 to form track sections a-b, 17-0, 0-11, de and 6- Each of these sections is provided with the usual track circuit comprising a battery 3'! and a track relay designated by the reference character 38 with a distinguishing exponent.

Adjacent the point e are signals designated by the reference characters S and S and adjacent the point (1 are signals designated by the reference characters S and S Each of these signals is of the light signal type shown in Fig. 1. SignalsS and S govern westbound trafiic movements, that is, trafiic movements from right to left as shcwnin the drawings, whereas signals s ands govern eastbound trafiic movements.

The circuits for secondary windings and aux iliary magnet windings 25 and 4! of signals and S are exactly similar to those shown in Fig. 1. The circuits for the corresponding windings of signals S and S however, differ from the circuits shown in Fig. 1, as will be explained herein-after. The operating winding 3 of each of the signals S S and S is provided with a circuit which includes a contact 33 of an associated track relay as in Fig. 2. The operating winding operated by the neutral armature of the next signal in advance as in Fig. 2, and is also supplied with current by a battery 29 as in Fig. 2.

In addition to the contacts shown in the circuit for operating winding 3 in Fig. 2, the circuits in Fig. 3 for windings 3 of signals S and S also include a back contact 46, operated by the mechanism of the next signal governing trafiic movements in the opposite direction, which is con nected in multiple with a front contact 45 of the track relay 38 for the first section in the rear of such opposing signal. The circuit for auxiliary winding 25 of each of the signals S and S does not include a contact of the associated track relay as in Fig. 2, but the circuit for winding 4! of signal S includes a normal polar contact 41 which is operated by the mechanism of signal S All parts of the apparatus of Fig. 3 are shown in their normal condition, that is, all track relays 38 are energized, and winding 3 of each of the signals S is energized by current of normal polarity for causing the signal to display a proceed (green) indication. The circuit by which winding 3 of signal S is energized passes from a battery 29, through a front contact of pole-changer 30 of signal S contact 45 of relay 38 contact 33 of relay 38, winding 3 of signal S and a second front contact of pole-changer 38 of signal S back to battery 25. Winding 3 of signal S is energized by'a circuit which is similar to the circuit just traced for signal S The circuit for winding 3 of signal S includes contact 33 of relay 38 and contact 43 of relay 38 as well as other contacts not shown in the drawings. Winding 3 of signal S is energized by a circuit similar to that just mentioned for signal S If, with all parts thus in their normal condition, an eastbound train enters section ab, deenergizing relay 38 the circuit for winding 3 of signal S will be opened at contact 48 of relay 38 thus deenergizing Winding 3 of signal S unless the circuit has previously been opened at some other point due to the approach of the eastbound train. The deenergization of winding 3 of signal S will cause this signal to display a stop indication, and will cause its pole-changer 30 to reverse the direction of flow of current to winding 3 of signal S Signal S will therefore display a caution indication.

When the train enters section bc, relay 38 will become deenergized and open its contacts 33 and 34 in the circuits for windings 3 and 25 of signal S and will also open its contact 55 in the circuit traced for winding 3 of signal With winding 30f signal S deenergized, signal S will display a stop indication.

When the train enters section c-ol, relay 38 will become deenergized, opening its contact 33 S winding 4 of thi'ssignalwill produce a surge of current, which will flow through contact 40-40 .of signal S and winding of this signal, tending to retain armature 1, sho wn in Fig; '1, in its attracted position. The mechanism of signal S is therefore slow releasing under this condition of train operation.

a, As the train proceeds further and enterssection d,-e, relay 38 will become deenergized, causing signal S to indicate" stop,'and opening contact 45 in the circuit for winding 3 of signal S The deenergization of winding 3 ofsignal S causes its pole-changer 30 to be reversed in the circuit for winding 3 of signal S a When the train leaves section d-e,'permitting relay 38 to become energized, winding 30f signal S will become energized. by current of reverse polarity. Signal S will therefore'display the caution indication.

When the train has proceeded far enough in the eastbound direction to permit winding 3 of signal S to again become energized, pole-changer 30 of this signal will be operated to its normal position, causing current of normal polarity to be supplied to Winding 3 of signal S which will then display the proceed indication,

If an eastbound train moving through the stretch of track shown in the drawings as just described were so short and moved so quickly past the insulated joints at point dthat relay 38 would close its front contact 33 before relay 38 could release, the normal energizing circuit for winding 3 of signal S would be completed for a brief period of time through contact 45 of relay 38 At this time, however, winding 4 of signal S on account of the energization of winding 3 of this signal, will produce a surge of current through contact |04l] of signal S polar contact 41 of this signal, and its winding 4|, which will tend to retain armature 1,-shown in Fig. 1 ,-in its deenergized position, thus making the mechanism of signal S slow to pick up. This slow pick-up feature of signal S will therefore prevent signal S from ialselydisplayi-ng the proceed indication 7 during the interval between the closing of contact 33 of relayp38 and thedropping of contact 45 of relay 38 a r a The operation of the apparatus for a westbound train movement is similar to that just described for an eastbound train movement. The circuit for winding 4| of signal S however, does not include a polar contact such as contact 41 which is shown in the circuit for winding 4| of signal S I will now assume that an eastbound train is approaching signal S and thata westbound train is approaching signal S the eastbound train causing winding3 of signal S to be deenergized and the westbound train causing winding 3 of signal S to be deenergized. Winding's'3 fofj'signals S and S are therefore'energized in the reverse direction. I will f urther assume that the westbound train enters section d''-e at the same instant that the eastbound train enters section b-c. i

- Relays 38 and 38 will, therefore, permit their front contacts 45 to open at the same instant. This will cause windings'3 of signals S and S to become deenergized at the same instant. Winding 4 of each of these signals will cause a surge of current to flow through its contact 4ll-4IJ toits winding 25, and hence the mechanism for each of these signals will be slow releasing. 1 1

Upon the closing of back contact 46 of signal S a reverse energizing circuit will be completed for winding 3 of signal S which is exactly the same as the energizing circuit previously described for this signal except that it includes contact 46 of signal S instead of contact 45 of relay 38 'A similar reverse energizing circuit will at the same instant become closed for'winding 3 of signal S through contact 46 of signal S On account of winding 3 of signal S having been energized in the reverse direction previous to its deenergization by the opening of contact 45 of relay 38 contact 41 of signal S is open, and hence when the circuit for Winding 3 of signal S is closed through back contact 46 of signal S there will be no surge of current through winding 4L| of signal S The mechanism of signal S will, therefore, be quick to pick up where as the mechanism of signal S will be slow to pick up since a surge of current will be supplied by winding 4 of signal S through its contact 4||----4|1I to its winding 4|. Hence the mechanism of signal S will open its contact 46 in the cir cuit'for signal S whereas contact 46 of signal S will remain closed in the circuit for winding 3 of signal S Signal S will, therefore, display the caution indication whereas signal S will display the stop indication.

Preference is thus given to an eastbound train in the event of an eastbound train entering section b--c at exactly the same instant that a westbound train enters section d,e This will prevent the alternate clearing of signals S and S under such a condition of train operation.

Although I have herein shown and described only two forms of systems embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. A railway signaling system comprising a plurality of track sections each provided with a track'circuit including a track relay, a signal for each section having an electromagnet provided with an operating winding and asecondary winding in inductive relation to the operating winding, each signal also including an armature controlled by the electromagnet and an auxiliary magnet arranged when energized to hold said armature closed, a circuit for the operating winding of each signal including a contact of the track relay for the associated section and a polechanger'operated by the armature of the next signal in advance, and a circuit for the auxiliary magnet of each signal including the associated secondary winding and a front contact of the track relay for the associated track cir- CUit. i

H 2. In-a railway signaling system, a section of track, .a signal adjacent each end of the section for governing traffic movements in opposite directions through the section, each of said signals having anelectrornagnet provided with an operating winding and a secondary winding in inductive relation to the operating Winding, each signal also including' an armature controlled by the electromagnet and an auxiliary magnet arranged when energized to hold said armature open, one of said signals also includwhen the operating Winding of said signal -is energized in the opposite direction for indicating caution, means controlled by traffic con-- ditions for causing said signals to normally display a proceed indication, means controlled by a train approaching within a given distance from each end of said section for causing the signal at the opposite end of the section to change from the proceed to the caution indication, a second section of track adjoining one end of said first section and provided with a track circuit including a track relay, a third section of track adjoining the opposite end of said first section and provided with a track circuit including a second track relay, a circuit including a front contact of said first track relay connected in multiple with a back contact of said one signal for controlling the caution indication of the other signal, a circuit including a front contact of said second track relay connected in multiple with a back contact of said other signal for controlling the caution indication of said one signal, a circuit for the auxiliary winding of said one signal including the associated secondary winding and said polar contact as well as a back contact of said one signal, and a circuit for the auxiliary winding of said other signal including only the associated secondary winding and a back contact of said other signal.

3. In combination, a first and a second section of railway track each provided with a track circuit including a track relay, a signal for governing traffic movements over said first toward said second section and having an electromagnet provided with an operating winding and a secondary winding in inductive relation to the operating winding, said signal also including an armature controlled by the electromagnet and an auxiliary magnet arranged when energized to hold said armature in its released position, said signal also having a polar contact closed when said operating winding is energized in the normal direction but open when said operating winding is energized in the reverse direction, a circuit including a front contact of the track relay for said first section in series with a front contact of the track relay for said second section for energizing said operating winding in the normal direction, and a circuit for said auxiliary magnet including said secondary winding and said polar contact.

4. In combination with a section of railway track provided with a track circuit, an electromagnetic device comprising an operating winding and a polarized armature and a neutral armature controlled thereby, signal means controlled by said armatures, a pole-changer controlled by traffic conditions in advance of said section for supplying said operating winding with current of one polarity or the other provided said section is unoccupied, a secondary winding in inductive relation with said operating winding, an auxiliary magnet effective when energized to retain said neutral armature in its operated position, and means controlled by said track circuit and effective when said section is unoccupied to connect said auxiliary magnet'with said secondary winding.

5. In combination with a section of railway track, an electromagnetic device having an opering a polar contact closed when the ,operati ngating winding controlled bysaid track circuit, a secondary winding inductively related with said operating winding, an armature controlled by said operatingwinding, a first magnet for holding said armature in'operated position, a second magnet for holding said armature'in released position, means including a contact closed when said armature is operated and a contact closed when said section is unoccupied for connecting said secondary winding with said first magnet, and means including a contact closed when said armature is released for connecting said secondary Winding with said second magnet. I

6. In a signaling system for a railway track divided into sections, a polarized relay for each section having polar and neutral armatures and having means normally making its neutral armature slow acting, signals for each section controlled by said neutral and polar armatures of its polarized relay, pole-changing contacts governed by the neutral armature on each such relay for supplying current of normal or reverse polarity to the corresponding polarized relay of a section in the rear, track circuits for said sections including track relays for the control of said polarized relays, and means controlled by the track relay of a section for changing the characteristics of the associated polarized relay so as torender its pole-changing contacts quick acting in dropping when that section becomes occupied.

'7. In a signaling system, a polarized relay, means for reversibly energizing said relay, means for deenergizing said relay, a second relay identical to the first relay, circuits for energizing said second relay in one direction including front neuo0 tral contacts of said first relay and for energizing it in the reverse direction through back neutral contacts of said first relay, means for preventing the dropping of the neutral contacts of said first relay on reversal of current therethrough, and means for disabling said last mentioned means when the said first relay is deenergized to reverse the direction of current flow through said second relay.

8. In combination with a forward section and a rear section of railway track, a pole-changer governed by traffic conditions in said forward section, a polarized relay governed by said polechanger as well as by trafiic conditions in the rear section and having a neutral armature, and a magnet effective only when said rear section is unoccupied and the armature is in its picked up condition for delaying the'release period of said armature.

9. In combination with a forward section and a rear section of railway track each provided with a track circuit including a track relay, a polechanger governed by the track relay for the forward section, a polarized relay including a neutral armature and governed by said pole-changer as well as by the track relay for the rear section, and means effective only when the track relay for the rear section is energized and the armature is in its picked up condition to delay the release period of said armature.

10. In combination with a forward section and a rear section of railway track, a pole-changer governed by traflic conditions in said forward section, a polarized relay including a neutral armature and governed by said pole-changer as well as by traific conditions in the rear section, means effective only when said rear section is unoccupied and the armature is in its picked up condition to delay the release period of said armature, and'means effective only when the armature 12. In combination with a forward section and a rear section of railway track, a pole-changer governed by traflic conditions in said forwardsection, a polarized relay governed by said polechanger as well as by trafiic conditions in said rear section and including a neutral armature, means for causing said armature to be slow in; picking up, and means for rendering said last mentioned means ineffective when said relay be-- comes energized in a particular direction.

PAUL H. CRAGO. 

